This invention relates generally to a closure assembly for sealing a chamber, and more specifically to, a closure assembly that allows high speed passage of objects into and out of a pyrolysis chamber, and which further allows a sealing of the pyrolysis chamber to facilitate a changing of the atmosphere within the chamber.
Known closure assemblies include knife gate valves and sliding gate valves which have a small distance between the two sides of the valve. Such valves are constructed such that a chamber, duct, or pipe flange to which the valve is connected, mates to a flange surface of the valve. Typically, the flanged surface has tapped holes to accept connecting bolts which minimizes a dead volume needed for operation of the door or valve. Unfortunately, this type of valve is not suited to high speed, high integrity gas tight sealing, because the seals are not highly reliable. For example, the seals wear as the valve is operated, and additionally, the seals cannot be changed without disassembling the valve. Further, there is no way to test the seal with the valve in service.
Sealing grooves within some of these valves are held in place by complicated keyway type cross-sections, making insertion and removal of seals extremely difficult, and making fabrication costly.
Some inflatable sealing assemblies are known to exist. However, these existing inflatable seal assemblies employ complicated and expensive cross sections that are custom made. Some of these assemblies have rectangular cross sections with varying wall thickness, some are molded with a complicated key way type geometry, or combinations of rectangular and curved edges making machining difficult. Further, to replace such a seal, the process which utilizes the sealing assembly, for example, the pyrolysis chamber described above, must be shut down and the door to which the seal is affixed is typically removed and disassembled, producing not only productivity losses but expensive repairs.
In addition, in certain known sealing assemblies there is no advance warning before the seals fail. The lack of advance warning typically causes the greatest cost and process disturbance. For example, as a seal in a pyrolysis chamber begins to fail, the effects of the seal leak become more damaging than just the effects to the pyrolysis process. For example, when a corrosive gas is allowed past the seal, other parts of the pyrolysis chamber can be damaged. As another example, if dust and debris leak past the seal erosion, plugging and mechanical damage can result.